The present invention relates to the field of interactive displays for use in oilfield services applications. In particular, the invention relates to a three-dimensional interactive display for rock stability applications relating to wellbore construction.
Wellbore instability and its associated drilling problems are a major source of lost time and excess cost when drilling. Planning for the management of instability is now becoming routine, but communicating information on instability prediction, for example to the diverse members of an asset or drilling team, can be difficult. This is because many parameters enter into the prediction, and displaying the influence of varying them all over their potential ranges is not possible with conventional charts or plots. There are also many outputs.
Three-dimensional displays for wellbore instability have been used in a demonstration drilling simulator. See, IADC/SPE 59121, When Rock Mechanics Met Drilling: Effective Implementation of Real-Time Wellbore Stability Control, I. D. R. Bradford, J. M. Cook, E. F. M. Elewaut, J. A. Fuller, T. G. Kristiansen, and T. R. Walsgrove (presented at the 2000 IADC/SPE Drilling Conference held in New Orleans, La., Feb. 23-25, 2000); and SPE/IADC 67816, Meeting Future Drilling Planning and Decision Support Requirements: A New Drilling Simulator, H.-L. Balasch, J. Booth, I. D. R. Bradford, J. M. Cook, J. D. Dowell, G. Ritchie, and I. Tuddenham (presented at the SPE/IADC Drilling Conference held in Amsterdam, The Netherlands, Feb. 27-Mar. 1, 2001). These displays were implemented using a scientific programming language known as Matlab.
Colored polar plots have been used to display the results of instability planning. For example polar colormap plots of the severity of potential instability for wells at different orientations have been implemented by Baker Hughes and Geomechanics International. These techniques show the influences of changing the well azimuth and deviation, with all other parameters fixed. The color used at a particular point in the polar plot depends on how much instability is predicted at the appropriate orientation. However, techniques such as these are of limited use due in part to the following:
1. the person viewing must have an appreciation of how a polar plot presents information; this is not a display method familiar to many people outside geology and crystallography;
2. the instability function must be integrated around the circumference of the well, in order to generate a single value for the colormap; this masks useful details of the circumferential variation (e.g., its potential use in image log interpretation); and
3. the plots are relatively slow to generate, since they have to cover a wide range of parameter space, but are then fixed; any change in the earth parameters means a time-consuming recalculation of the whole plot.
Finally, Three-dimensional displays have recently been used successfully to convey instability information for a fixed trajectory in a fixed earth model. However, these techniques suffered in that they were not interactive with the user. This is primarily because if the parameters of the trajectory or earth model are changed, considerable recomputation is required to display the new results, and there is no user-friendly method of changing the trajectory of the wellbore.
Thus, it is an object of the present invention to provide a system and method for interactively displaying rock stability information to a user in three-dimensions.
According to the invention a system is provided for interactively displaying estimated stability of rock surrounding a wellbore comprising:
a three-dimensional display adapted to display to a user an orientation of a portion of the wellbore and an estimation of stability of the rock surrounding the portion of the wellbore;
a user input system adapted to accept user input representing changes in orientation of the portion of the wellbore; and
a processing system adapted to accept the user input from the user input system and calculate and communicate to the display a revised estimation of stability of the rock based on the user input.
Also according to the invention, a method is provided for interactively displaying estimated stability of rock surrounding a wellbore comprising the steps of:
displaying to a user a three-dimensional representation of a first orientation of a portion of the wellbore and a first estimation of stability of the rock surrounding the portion of the wellbore associated with the first orientation;
receiving user input representing a second orientation of the portion of the wellbore;
calculating a second estimation of stability of the rock associated with the second orientation; and
displaying to the user in real time a three-dimensional representation of the second orientation of the portion of the wellbore and the second estimation of stability of the rock.